Commit fbdee71b authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: deprecate autoloading based on dev_t 



Make the legacy dev_t based autoloading optional and add a deprecation
warning.  This kind of autoloading has ceased to be useful about 20 years
ago.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220104071647.164918-1-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 26291c54

block/Kconfig

+12 −0
Original line number Diff line number Diff line
@@ -26,6 +26,18 @@ menuconfig BLOCK 


if BLOCK



config BLOCK_LEGACY_AUTOLOAD

	bool "Legacy autoloading support"

	help

	  Enable loading modules and creating block device instances based on

	  accesses through their device special file.  This is a historic Linux

	  feature and makes no sense in a udev world where device files are

	  created on demand.



	  Say N here unless booting or other functionality broke without it, in

	  which case you should also send a report to your distribution and

	  linux-block@vger.kernel.org.



config BLK_RQ_ALLOC_TIME

	bool

block/bdev.c

+6 −3
Original line number Diff line number Diff line
@@ -733,12 +733,15 @@ struct block_device *blkdev_get_no_open(dev_t dev) 
	struct inode *inode;



	inode = ilookup(blockdev_superblock, dev);

	if (!inode) {

	if (!inode && IS_ENABLED(CONFIG_BLOCK_LEGACY_AUTOLOAD)) {

		blk_request_module(dev);

		inode = ilookup(blockdev_superblock, dev);

		if (inode)

			pr_warn_ratelimited(

"block device autoloading is deprecated. It will be removed in Linux 5.19\n");

	}

	if (!inode)

		return NULL;

	}



	/* switch from the inode reference to a device mode one: */

	bdev = &BDEV_I(inode)->bdev;

block/genhd.c

+6 −0
Original line number Diff line number Diff line
@@ -185,7 +185,9 @@ static struct blk_major_name { 
	struct blk_major_name *next;

	int major;

	char name[16];

#ifdef CONFIG_BLOCK_LEGACY_AUTOLOAD

	void (*probe)(dev_t devt);

#endif

} *major_names[BLKDEV_MAJOR_HASH_SIZE];

static DEFINE_MUTEX(major_names_lock);

static DEFINE_SPINLOCK(major_names_spinlock);
@@ -275,7 +277,9 @@ int __register_blkdev(unsigned int major, const char *name, 
	}



	p->major = major;

#ifdef CONFIG_BLOCK_LEGACY_AUTOLOAD

	p->probe = probe;

#endif

	strlcpy(p->name, name, sizeof(p->name));

	p->next = NULL;

	index = major_to_index(major);
@@ -679,6 +683,7 @@ static ssize_t disk_badblocks_store(struct device *dev, 
	return badblocks_store(disk->bb, page, len, 0);

}



#ifdef CONFIG_BLOCK_LEGACY_AUTOLOAD

void blk_request_module(dev_t devt)

{

	unsigned int major = MAJOR(devt);
@@ -698,6 +703,7 @@ void blk_request_module(dev_t devt) 
		/* Make old-style 2.4 aliases work */

		request_module("block-major-%d", MAJOR(devt));

}

#endif /* CONFIG_BLOCK_LEGACY_AUTOLOAD */



/*

 * print a full list of all partitions - intended for places where the root